The present invention relates to processes for purifying impure psyllium husk using fluorinated hydrocarbons. The present invention also relates to psyllium husk having greater than about 99% purity prepared by a process of the present invention.
Products containing psyllium seed husk are used in high fiber food products and/or health care products for the benefit of normalizing bowel function and laxations. In addition, research has demonstrated the effectiveness of psyllium seed husk fiber in reducing human serum cholesterol levels, and in controlling blood glucose levels in diabetics. See, for example, J. W. Anderson, et al, Fed. Proc., 46, 877 (1987); J. W. Anderson, et al, Am. J. Gastroenterology, 81, 907-919 (1986); and S. Faberberg, Curr. Ther. Res., 31, 166 (1982); all incorporated here and by reference in their entirety.
Psyllium seed husk is typically manufactured by separating the seed husk from the remainder of the seed by slight mechanical pressure, for example by crushing the seeds between rotating plates or rollers. The husk is then typically purified by sieving the mixture to separate the husk from the remainder of the seed parts and/or by blowing (winnowing) the husk away from the impurities. Impurities present in the psyllium husk are predominately sand and dark particles which are readily visually apparent amongst the blond-colored psyllium husks; and these are readily perceived as being particularly gritty during ingestion. Subsequent attempts at purifying the psyllium husk further, for example by sieving and/or gravity tables, are generally tedious processes which produce low yields of psyllium husk and/or only moderately improved purity.
It has been discovered that purification of impure psyllium husks can be achieved easily and efficiently by using liquid fluorinated hydrocarbons having a density within a range suitable for differentiating and separating psyllium husk from more dense and/or less dense impurities present in the husk. By the present invention process, psyllium husk having high purity can be obtained with very little loss in yield of the psyllium husk. Furthermore, psyllium husk prepared by this process which is greater than about 99% pure has also demonstrated significantly reduced allergenicity.
It is therefore an object of the present invention to provide processes for the fast, efficient and safe purification of impure psyllium husk. It is also an object to provide high purity psyllium husk having reduced allergenicity.
These and other objects of the present invention will become readily apparent from the detailed description which follows.
All percentages and ratios used herein are by weight, and all measurements are made at 25.degree. C., unless otherwise specified.